Peripheral GZMB+CD4+ CTLs are expanded in DM and ASS and are closely associated with disease activity, while their diagnostic performance suggests that they may serve as a biomarker and potential therapeutic target in these diseases.
Abstract
Background Dermatomyositis (DM) and antisynthetase syndrome (ASS) are heterogeneous subsets of idiopathic inflammatory myopathies with persistent unmet needs in disease activity assessment and stratification. Although CD4+ T cells are recognized as important contributors to disease pathogenesis, the role of CD4+ cytotoxic T lymphocytes (CTLs) remains insufficiently defined. Methods Peripheral blood samples were collected from patients with DM (n = 50), patients with ASS (n = 14), and healthy donors (HDs, n = 20). The frequency of CD4+ cytotoxic T lymphocytes with expression of cytotoxic protein granzyme B (GZMB+CD4+ CTLs) was analyzed by flow cytometry to quantify GZMB+CD4+ CTLs and characterize their phenotype. Disease activity and severity were evaluated using standard clinical indices. Multiplex immunohistochemistry was performed on skin biopsy specimens from patients with DM (n = 4) to assess tissue infiltration and endothelial injury. Results The proportion of circulating GZMB+CD4+ CTLs was significantly increased in both DM and ASS compared with HDs. In patients, this population showed phenotypic features consistent with enhanced cytotoxicity and tissue trafficking, including increased fibroblast growth factor binding protein 2 (FGFBP2) expression and reduced circulating fractions of cells positive for C-X3-C motif chemokine receptor 1 (CX3CR1) and C-X-C motif chemokine receptor 3 (CXCR3). GZMB+CD4+ CTL frequency was positively associated with global disease activity and cutaneous activity, and decreased after treatment independently of specific drug regimens. Receiver operating characteristic analysis showed that circulating GZMB+CD4+ CTLs effectively distinguished active from remitting disease in both DM and ASS. In DM skin lesions, GZMB+CD4+ CTLs were abundant and were accompanied by increased endothelial apoptosis and enhanced HLA-DR expression. Conclusions Peripheral GZMB+CD4+ CTLs are expanded in DM and ASS and are closely associated with disease activity. Their accumulation in lesional tissue and association with endothelial injury support a potential pathogenic role, while their diagnostic performance suggests that they may serve as a biomarker and potential therapeutic target in these diseases.
OBJECTIVE
Systemic sclerosis (SSc) is characterized by immune dysregulation and fibrosis. We investigated whether abatacept modulates CD319/SLAMF7-expressing cytotoxic T cells implicated in diffuse cutaneous SSc.
METHODS
In this ancillary ASSET trial analysis, PBMCs from 67 participants were analyzed at baseline and months 1, 3, and 6. Flow cytometry quantified CD4+CD319+ and CD8+CD319+ T cells, cytotoxic/activation markers, and stimulated intracellular IL-4, IL-17A, and IFN-γ. Analyses compared abatacept-treated molecular endotypes with placebo and related immune changes to modified Rodnan skin score (mRSS) change. Skin single-cell RNA sequencing included 5 healthy controls and 8 SSc patients.
RESULTS
At baseline, CD319+ T cells showed greater cytokine production, activation, and granzyme/perforin expression than CD319- T cells in 60 evaluable participants (p<0.001 to p<0.0001). Abatacept reduced CD4+CD319+ and CD8+CD319+ T cell frequencies at month 6; placebo did not. Effects were strongest in fibroproliferative patients, where CD8+CD319+ T cells decreased versus placebo (n=7 versus n=36; p=0.0377). In this endotype, abatacept reduced IL-4 in CD4+CD319+ and CD8+CD319+ T cells at month 3 (p=0.0468 and p=0.0287) and IL-17A in CD8+CD319+ T cells at month 6 (p=0.0004), while IFN-γ was unchanged. Reduction in CD4+CD319+ T cells correlated with mRSS improvement in abatacept-treated patients (r=0.5297, p=0.0423). Skin single-cell RNA-sequencing showed increased SLAMF7 expression in SSc T cells (p=0.017), enriched within cytotoxic subsets.
CONCLUSION
CD319+ T cells represent highly differentiated, activated cytotoxic effector populations in SSc. Abatacept selectively modulates these cells and suppresses associated pro-fibrotic and pro-inflammatory cytokines, particularly in the fibroproliferative subtype, where CD319+ T cell reductions correlate with clinical improvement.
Mikel Gurrea-Rubio, Laura A. Cooney, Kohei Maeda et al.· Arthritis & Rheumatology· 0 citations
Background/aim: Alopecia areata (AA) is a nonscarring hair loss disorder characterized by genetic susceptibility, environmental triggers, and T-cell–mediated autoimmunity. While various CD4+ and CD8+ T-cell subsets are implicated in its pathogenesis, the roles of follicular T-cell (Tfh), peripheral T-cell (Tph), and regulatory T-cell (Treg) subsets– particularly within the CD8+ population–remain incompletely defined. This study aimed to characterize circulating CD4+ and CD8+ T-cell subsets in Turkish patients with AA and to evaluate their associations with disease activity, duration, and severity.
Materials and methods: A total of 40 patients with AA and 40 healthy controls were enrolled. CD4+ and CD8+ T-cell subsets—including Th1, Th2, Th17, Th22, Tc1, Tc2, Tc17, Tc22, Treg, Tfh, and Tph cells—were analyzed by flow cytometry based on surface marker expression and intracellular cytokine profiles. Disease severity was assessed using the Severity of Alopecia Tool (SALT) score, and disease activity was evaluated by the hair pull test.
Results: Patients with AA exhibited significantly lower frequencies of Tc17 and Tc22 cells than healthy controls. CD4+ Tfh cell levels were positively correlated with disease duration. CD4+ Tregs, resting Tregs, CD3+IL-4+ cells, and Tc2 cells were positively associated with SALT scores, whereas CD4+ and CD8+ Tph cells were inversely associated. CD8+ T-cell populations, CD4+ Treg subsets, CD3+IFN-γ+ cells, Th1 cells, and Th2 cells were associated with disease activity, as assessed by the hair pull test.
Conclusion: Alopecia areata is associated with alterations in circulating T-cell subsets, particularly Tc17 and Tc22 subsets. Selected cytokine-producing and regulatory T-cell subsets are associated with disease activity. These findings support a heterogeneous and dynamic immune profile in AA and highlight the importance of multivariate approaches in identifying independent immunological correlates. Further studies integrating tissue-level analysis and longitudinal follow-up are needed to clarify the underlying mechanisms.
Hatice Türk Daği, H. Ozdemi̇r, Mehmet Akyürek et al.· Turkish Journal of Medical S...· 0 citations
Sjögren's disease (SjD) is an autoimmune condition marked by exocrine gland damage, lymphocytic infiltration, and autoantibody production. Recently, extrafollicular B cells have been implicated in autoimmune diseases, yet their specific role and characteristics within SjD remain largely unknown. Therefore, we aim to evaluate the distribution of atypical memory B cells (aMBCs) in patients with SjD and correlate them with clinical features. Forty SjD patients and 34 healthy subjects (HS) were included. Identification of aMBCs (CXCR5-CD11c+) subsets was performed, then expression of CD21 and CD38 were assessed in aMBCs subpopulations. SjD patients exhibited a systemic expansion of extrafollicular B cells, including aNAV, DP NAV, and DN2, DN3, and DN4 populations (P < 0.001). ANCOVA revealed that DN2 expansion is uniquely independent of chronological aging (P = 0.006). Analyzed CD19+ B cells using high-dimensional t-SNE and biaxial gating showed that aMBCs displayed heightened CD38 expression, signaling an activated phenotype primed for plasma cell differentiation. Furthermore, inverse correlations between DP NAV and USM frequencies and clinical scores (clinESSDAI, SSDDI) suggest possible sequestration within salivary glands or functional exhaustion. This pathogenic signature, manifesting as early as the naïve stage, underscores the aNAV-DN2 axis as a central hallmark of B-cell dysregulation in SjD.
Victor Manuel Menchaca-Tapia, P. Ortiz-Lazareno, N. Espinoza-García et al.· Scientific Reports· 0 citations
A divergent regulation of CD29 and CD49b integrins associated with HLA-B27 status in Iraqi AS patients is suggested and longitudinal validation is required to confirm their clinical utility as diagnostic or therapeutic targets.
Ahmed Ali Alshammari, M. Mohsin· Iranian Journal of Pathology· 0 citations
The article describes a 57-year-old female patient with lesions of the scalp, trunk and extremities, who was diagnosed with scleromyxedema (myxedematous lichen) by a dermatovenereologist based on clinical data and histopathological examination of a skin biopsy. An immunochemical study of serum proteins revealed an M-gradient in the g3 zone, formed by a Gk clone and amounting to 4.9 g/l. Immunophenotyping of blood cells revealed a population of clonal plasma cells with the CD138+CD38+ CD56-CD10-CD117-kappa immunophenotype (2.26% of all studied events). Upon further examination by a hematologist, 2% of plasma cells were detected in the myelogram. Immunophenotyping of bone marrow cells by flow cytometry revealed 0.144% of plasma cells from all cells with the aberrant immunophenotype CD38dimCD138+CD319+CD19-CD45+/-CD56+/- CD27+/-CD117-/+CD200+CD20-/+. No criteria for symptomatic multiple myeloma or smoldering myeloma were found. The patient was diagnosed with monoclonal gammapathy of clinical significance, with a predominant total skin lesion, scleromyxedema, occurring with monoclonal secretion of Gk. The VRD therapy (bortezomib, lenalidomide, dexamethasone) followed by autologous hematopoietic stem cell transplantation has achieved significant improvement. Gk secretion decreased to a trace, the bone marrow was sanitized, and a significant improvement in the patient's skin condition was noted. The presented case demonstrates the association of scleromyxedema with monoclonal gammapathy and indicates the need to examine patients with scleromyxedema by a hematologist.
V. Chikin, M. Soloveva, A. Kovrigina et al.· Vestnik Dermatologii i Vener...· 0 citations
Background Sjögren’s disease (SjD) is a systemic autoimmune disease showing clinical characteristics similar to systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) at early phases, complicating diagnosis. Methods In this cross-sectional study, blood was obtained from 65 SjD, 34 SLE, and 44 SSc patients and 56 healthy donors (HD). Numbers and percentage of circulating leukocytes and expression of HLA-DR, PSGL-1, ADAM8, IL-10 and IFNα were determined by flow cytometry. Results Compared to HD, SjD patients showed generalized immune system activation and global reduction of circulating leukocytes, except for plasma cells, which were increased. IFNα levels were reduced in SjD CD16- monocytes, dendritic cells (DC), B cells and basophils, but increased in SjD CD16+ monocytes and T cells, showing a positive correlation between IFNα T cell levels and percentage of circulating plasma cells. ADAM8 expression levels were reduced in CD16+ monocytes and B cells. In plasma cells and plasmablasts reduction of ADAM8 expression levels were observed during disease activity. SjD patients had reduced percentage of PSGL-1+ neutrophils and increased percentage of PSGL-1+ B cells (PS1B), which expressed higher levels of IL-10 than those from HD. Low percentage of PSGL-1-expressing neutrophils, basophils, T cells and NK cells and low PSGL-1 expression level in pDC associated with the presence of cutaneous manifestations. Low PSGL-1 expression level in basophils, cDC and both CD16- and CD16+ monocytes was associated with the presence of anti-SSB autoantibodies. Remarkably, we found two cellular biomarkers: PS1B/%pDC ratio (PPr) distinguished SjD patients from HD (accuracy: 78%) and from SSc (accuracy: 84%) and PS1B discriminated SjD from SLE (accuracy: 70%). Both biomarkers improved diagnostic accuracy when combined with current serological markers. Conclusions Dysregulated PSGL-1 and ADAM8 expression in SjD circulating cells is associated with important clinical manifestations in SjD patients, supporting their potential relevance as therapeutic targets in this disease. Additionally, we found PS1B and PPr as new cellular biomarkers that could help improve SjD diagnostic accuracy, particularly in seronegative or ambiguous cases during the early phase of disease.
Alejandra Ramos-Manzano, I. Sánchez-Abad, E. San Antonio et al.· Frontiers in Immunology· 0 citations
